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Scales of snow depth variability in high elevation rangeland sagebrush

Frontiers of Earth Science 2017年第3期11卷 469-481页

作者： Molly E. TEDESCHE Steven r. FASSNACHT Paul J. MEIMAN Watershed Science Department of Ecosystem Science and Sustainability Colorado State University Fort Collins CO 80523-1476 USA Intemational Arctic research Center Water & Environmental Research Center Institute of Northern Engineering University of Alaska Fairbanks Fairbanks AK 99775 USA Cooperative Institute for research in the Atmosphere Fort Collins CO 80523-1375 USA Natural resources Ecology Laboratory Fort Collins CO 80523-1499 USA Abt. Kartographie GIS & Femerkundung Geographisches Institut Georg-August-Universitat Gottingen 37077 Gottingen Germany rangeland Ecosystem Science Department of Forest and Rangeland Stewardship Colorado State University Fort Collins CO 80523 USA

In high elevation semi-arid rangelands, sage- brush and other shrubs can affect transport and deposition of wind-blown snow, enabling the formation of snowdrifts. Datasets from three field experiments were used to investigate the scales of spatial variability of snow depth around big mountain sagebrush （Artemisia tridentata Nutt.） at a high elevation plateau rangeland in North Park, Colorado, during the winters of 2002, 2003, and 2008. Data were collected at multiple resolutions （0.05 to 25 m） and extents （2 to 1000 m）. Finer scale data were collected specifically for this study to examine the correlation between snow depth; sagebrush microtopogra- phy, the ground surface, and the snow surface, as well as the temporal consistency of snow depth patterns. Vario- grams were used to identify the spatial structure and the Moran＇s I statistic was used to determine the spatial correlation. results show some temporal consistency in snow depth at several scales. Plot scale snow depth variability is partly a function of the nature of individual shrubs, as there is some correlation between the spatial structure of snow depth and sagebrush, as well as between the ground and snow depth. The optimal sampling resolution appears to be 25-cm, but over a large area, this would require a multitude of samples, and thus a random stratified approach is recommended with a fine measurement resolution of 5-cm.

关键词： snow hydrology high elevation rangelands,spatial statistics variograms snow pack spatial variability,snow drifts

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reliability Assessment of a Cyber Physical Microgrid System in Island Mode

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CSEE Journal of Power and Energy Systems 2019年第1期5卷 46-55页

作者： Jing Guo Wenxia Liu Furqan r.Syed Jianhua Zhang State Key Laboratory of Alternate Electrical Power System with renewable Energy Sources North China Electric Power UniversityBeijing 102206China GCL New Energy Suzhou 215000China

As cyber physical systems,microgrids(MGs),with distributed generations and energy management systems,can improve the reliability of power supply for customers in *** quantify the reliability of isolated MGs,a cyber-physical assessment model is *** this model,the circuit breakers and distributed energy resources are treated as the coupling elements between the cyber system and physical system,where the circuit breakers are uniquely modelled by using the Markov process theory based on the indirect interdependencies between cyber physical *** the cyber system,the reliability model of communication networks is formulated based on the link connectivity evaluation *** the physical system,a system state generating method is presented to account for the optimal operation strategy,which considers the influence of the optimization strategy on the failure consequence *** the proposed cyber and physical reliability models,the sequential Monte Carlo(SMC)simulation method is adopted to assess the reliability of islanded *** are carried out on a test system,and results verify the feasibility and effectiveness of proposed assessment ***,one application of the proposed method is on the parameter setting of the cyber system,in terms of enhancing MGs reliability.

关键词： Cyber physical system island mode microgrid reliability assessment sequential Monte Carlo

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Approximate Bound State Solutions of DKP Equation for Any J State in the Presence of Woods-Saxon Potential

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Communications in Theoretical Physics 2012年第1期57卷 15-18页

作者： r.Oudi S.Hassanabadi A.A.rajabi H.Hasanabadi Physics Department Shahrood University of TechnologyShahroodIran

We study Duffin-Kemmer-Petiau(DKP) equation in the presence of the Woods-Saxon potential and obtain eigenvalues and corresponding eigenfunctions for any J state by using of the Nikiforov-Uvarov(NU) *** Pekeris approxi... 详细信息

关键词： DKP equation Woods-Saxson potential Pekeris approximation NU method

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Erratum to:Estimating the maximum impact force of dry granular flow based on pileup characteristics

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Journal of Mountain Science 2022年第7期19卷 2138-2138页

作者： XIAO Si-you SU Lijun JIANG Yuan-jun MEHTAB alam LI Cheng LIU Dao-chuan Key Laboratory of Mountain Hazards and Earth Surface Processes and Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu610041China University of Chinese Academy of Sciences Beijing100049China CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing100101China Sichuan Highway Planning DesignResearch Institute LtdChengdu610041China

The Acknowledgements chapter is missing in the original article The Acknowledgements chapter should beas *** The authors give sincere acknowledgement to Strategic Priority research Program of Chinese Academy of Sciences(XDA 20030301)and the National Natural Science Foundation of China(Grant No.41761144077)for the completion of this *** research presented in this paper was also jointly supported by the CAS Pioneer Hundred Talents Program and the National Natural Science Foundation of China(Grant No.41502334).

关键词： jointly Pioneer characteristics

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PIECEWISE ANALYSIS OF OBLIQUE VIBrO-IMPACTING SYSTEMS

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Acta Mechanica Sinica 2003年第6期19卷 579-584页

作者：金栋平胡海岩 Steven r.BISHOP Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

A great number of studies have shown the complex nonlinear dynamics of mechanical systems with repeated normal impacts. An oblique frictional impact introduces even more complicated dynamics such as stick-slip motions to those systems. Hence, the dynamics of oblique vibro-impacting systems with possible sliding motion is an open problem. Based on a hybrid analysis of vibro-impact dynamics, kinematics and complementary conditions, a piecewise analysis method is developed in the paper to describe the sliding motion during an oblique impact. Thereby, a parametrically excited planar pendulum between two parallel rigid walls is studied as an illustrative example. The example, together with the corresponding numerical results, shows that the sliding impacts occur in such a system with a set of properly selected parameters.

关键词： nonlinear dynamics oblique impact sliding motion piecewise analysis

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Non-invasive image processing method to map the spatiotemporal evolution of solute concentration in two-dimensional porous media

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Journal of Hydrodynamics 2018年第4期30卷 758-761页

作者：钱家忠王泽坤 r.M.Garrard Yong Zhang 马雷 School of resources and Environmental Engineering Hefei University of Technology The 3rd Engineering Co. LTD of China Railway 16thBureau Group Department of Geological Sciences University of Alabama State Key Laboratory of Hydrology-Water resources and Hydraulic Engineering Hohai University

A color visualization-based image processing method is developed in this paper to quantify the concentration evolution of the Brilliant Blue FCF transport through a two-dimensional homogeneous porous medium. A series of images are recorded at known time intervals, then the spatial distribution is estimated using a calibration curve, linking the gray pixel value to the solute concentration. Using a multi-dimensional concentration distribution map extraction technique the longitudinal and transverse concentration distributions could be observed with the physical model. The image-processed concentrations are then compared directly with the measured concentrations sampled at the outlet end. The tracer breakthrough curves sampled at multiple points along the central line of the medium are also compared with the solutions from the standard advection–dispersion equation model. It is shown that the non-invasive image processing method may be used to map the spatiotemporal evolution of a solute＇s concentration without disturbing the flow or the transport dynamics, although the measured solute breakthrough curves feature some non-Fickian dynamics that cannot be efficiently captured by the standard transport model.

关键词： Solute transport color tracer porous media image processing method

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Endoscopic management of postcholecystectomy biliary leakage

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Hepatobiliary & Pancreatic Diseases International 2010年第4期9卷 409-413页

作者： Virendra Singh Gurpreet Singh Ganga r Verma rajesh Gupta Departments of Hepatology Postgraduate Institute of Medical Education and Research Departments of Surgery Postgraduate Institute of Medical Education and Research

BACKGrOUND: Biliary leak is an uncommon but significant complication following cholecystectomy. Endotherapy is an established method of treatment. However, the optimal intervention is not known. METHOD: Eighty-five patients with postcholecystectomy biliary leaks from July 2000 to March 2009 were retrospectively evaluated. rESULTS: The study population was 20 males and 65 females with a mean age of 42.47 years. Patients presented with abdominal pain (46), jaundice (23), fever (23), abdominal distension (42), or bilious abdominal drain (67). Endoscopic retrograde cholangiopancreatography detected a leak at the cystic duct stump in 45 patients, stricture with middle common bile duct leak in 4, leak from the right hepatic duct in 3, and a ligated common bile duct in 32. Twelve also had bile duct stones. One had a broken T-tube with stones Endotherapy was possible in 53 patients. Three patients with stones, one with a broken T-tube with stones, and 4 with stricture of the common bile duct with a leak were managed with sphincterotomy and stenting. Eight patients with a cystic duct stump leak with stones were managed with sphincterotomy and stone extraction. Three outpatients and 12 inpatients with a cystic duct stump leak were managed with sphincterotomy and stent and sphincterotomy and nasobiliary drain, respectively. Five patients with a cystic duct stump leak were managed with stenting. Sixteen with coagulopathy were managed with only nasobiliary drain (9) or stent (7). Leak closure was achieved in 100% patients Four developed mild pancreatitis which improved with conservative ***: Endoscopic intervention is a safe and effective method of treatment of postcholecystectomy biliary leaks. However, management should be individualized based on factors such as outpatients or inpatients, presence of stone, stricture, ligature, or coagulopathy.

关键词： biliary fistulae endoscopic retrograde cholangiopancreatography sphincterotomy biliary stent nasobiliary drain biliary strictures

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Effect of physiological integration in self/non-self genotype recognition on the clonal invader Carpobrotus edulis

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Journal of Plant Ecology 2014年第4期7卷 413-418页

作者： Sergio r.roiloa Susana rodríguez-Echeverría Helena Freitas Department of Life Sciences Centre for Functional EcologyUniversity of CoimbraCalçada Martim de Freitas3001-455 CoimbraPortugal

Aims biological invasions represent one of the most important threats to the conservation of biodiversity;however,the mechanisms underlying successful invaders remain *** of the most aggres-sive invaders show clonal growth,and capacity for clonal integration has been pointed out recently as an important trait explaining the success of invasive *** aim to determine the role of physi-ological integration in the capacity for self/non-self genotype recog-nition in the clonal invader Carpobrotus edulis and the implications of this capacity for the expansion of this aggressive *** We used connected and severed ramets of identical or different gen-otype and we determined the capacity for self/non-self recognition by comparing changes in biomass partitioning to avoid competition for resources between pairs of *** Findings Physiological integration allowed self/non-self genotype recogni-tion in the invader *** showed a significant effect of physiological integration on the biomass allocated to roots by genetically identical ramets:older ramets specialize in acqui-sition of soil-based resources and younger ramets specialize in lateral *** specialization could be considered a form of division of labour,which reduce intra-genotype *** is the first evidence that division of labour could be inter-preted as a form of self/non-self recognition between genetically identical *** for self/non-self discrimination could contribute to increase the colonization capacity of the aggressive invader *** is the first study showing an association between self/non-self recognition and invasiveness in a clonal plant.

关键词： biomass allocation clonal growth plant invasions root recognition

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Enhanced Security with Improved Defensive routing Mechanism in Wireless Sensor Networks

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Computer Systems Science & Engineering 2023年第6期45卷 2795-2810页

作者： r.Sabitha C.Gokul Prasad S.Karthik Department of Computer Science&Engineering SNS College of TechnologyCoimbatoreTamilnaduIndia Department of Electronics and Communication Engineering SNS College of EngineeringCoimbatoreTamilnaduIndia

In recent scenario of Wireless Sensor Networks(WSNs),there are many application developed for handling sensitive and private data such as military information,surveillance data,tracking,***,the sensor nodes of WSNs are distributed in an intimidating region,which is non-rigid to *** recent research domains of WSN deal with models to handle the WSN communications against malicious attacks and *** traditional models,the solution has been made for defending the networks,only to specific ***,in real-time applications,the kind of attack that is launched by the adversary is not ***,on developing a security mechanism for WSN,the resource constraints of sensor nodes are also to be *** that note,this paper presents an Enhanced Security Model with Improved Defensive routing Mechanism(IDrM)for defending the sensor network from various ***,for efficient model design,the work includes the part of feature evaluation of some general attacks of *** IDrM also includes determination of optimal secure paths and Node security for secure routing *** performance of the proposed model is evaluated with respect to several factors;it is found that the model has achieved better security levels and is efficient than other existing models in WSN *** is proven that the proposed IDrM produces 74%of PDr in average and a minimized packet drop of 38%when comparing with the existing works.

关键词： Enhanced security model wireless sensor networks improved defensive routing mechanism secure paths node security

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Evaluation of thermal imaging system and thermal radiation detector for real-time condition monitoring of high power frequency converters

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Advances in Manufacturing 2014年第1期2卷 88-94页

作者： Anders Eriksen D. Osinski D. r. Hjelme Department of Electrical and Computer Engineering Faculty ofTechnology SOr-TrCndelag University College TrondheimNorway

We have carried out at laboratory test to study the feasibility of using thermal radiation detectors for online thermal monitoring of electrical systems in wind turbines. A 25 kW frequency converter is instrumented with a thermal camera, operating in the 8-14 μm wave- length range, and a single-pixel thermopile sensor, operating in the 4-8 μm wavelength range, to monitor the temperature development of the power electronics under various load sequences. Both systems performed satisfactorily with insignificant temperature deviations when compared to data from calibrated point contact sensor. With spatial averaging over a 7 mm × 7 mm for the camera and temporal averaging over 60 s for the thermo- pile sensor, we reduce the root mean square noise to 45 mK and 68 mK respectively. The low cost and simple operation of the thermopile sensor make it very attractive for condition monitoring applications, whereas the attractive feature of the camera is the possibility of multi-point or distributed temperature measurements.

关键词： Temperature measurement Conditionmonitoring Frequency converter Wind turbine

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